1. Field
The present invention relates to the fields of toys and construction sets. More specifically, the present invention relates to a plurality of detachably chainable links capable of being pivotally attached to one another to form stable geometric structures.
2. Art Background
Interlocking links have been used for toys, electrical connectors, ornamental chains, index chains and chain links. One toy distributed by Matchbox Toys under the LINK.multidot.IT trademark included pieces for building a chain or other geometric shape from a number of links. A chain of electrical connectors linked end-to-end in the direction of their length is taught by John C. Collier in U.S. Pat. No. 4,360,969. Ornamental chains and necklaces are taught by H. Becker in U.S. Pat. No. 2,699,035; G. R. S. Charles in U.S. Pat. No. 2,714,269; G. R. S. Charles et al in U.S. Pat. No. 3,066,501; and H. Meyer in U.S. Pat. No. 3,323,325. G. K. Hall teaches a flexible index strip in U.S. Pat. No. 2,805,084. R. D. Johnson teaches a detachable chain link in U.S. Pat. No. 2,618,922. With the exception of the LINK.multidot.IT.TM. product, these chainable links were not intended for use in a children's construction set. However, while the LINK.multidot.IT.TM. product does provide a tactile feel, an audible sound and indexing for certain positions where the links are coupled at angles of zero and plus or minus ninety degrees in one plane, it does not provide tactile feel, an audible sound or indexing when the additional links are coupled to construct a three dimensional structure. Further, no indexing is provided intermediate to the zero and ninety degree positions. Another prior art linkable chain has been distributed under the LEGO.TM. trademark in association with the arm of a robot. However these links were restricted to the construction of clains in 2 dimensions and had no detents for indexing the angular positions between links.
It is desirable for a construction set to be capable of providing a precise and stable three-dimensional structure. Unfortunately, prior art products are either unstable or incapable of being arranged in arbitrary three-dimensional structure. For example, most of the prior art chainable links are designed to freely rotate or freely pivot between links. The LINK.multidot.IT product apparently holds its pivotal position only because of friction between links. This is not sufficient to provide a suitably stable structure. Further, the non-indexed pivotal engagement of the links makes it difficult to align two links in a precise manner. Finally, many prior art chainable links are free to rotate in an unrestricted manner in any direction, such as the ball-and socket stringless necklace beads taught by G. R. S. Charles et al in U.S. Pat. No. 3,066,501. This makes it nearly impossible to build precise geometrical structures. Alternatively, many prior art pivotal links are limited to a single plane.
Accordingly, it is desirable to provide a construction set made up of releaseably attachable chainable links that can form a stable and precise three-dimensional geometric shape. Further, it is desirable that the positions between links be indexed and that a good tactile feel and/or audible feedback be provided when an indexed position is reached.